Times vary depending on the veggie. Asparagus only takes about 10-15 minutes. Broccoli and cauliflower are closer to 20-25 minutes, and rutabaga can take up to 40 minutes. I just watch for the browning

If you are a garlic fan (like me), roast them in "shell" but separated from the bulb. I usually roast my veggies (usually Zucchini, asparagus, bell peppers, mushrooms and garlic) for 20 minutes at 350 with a bit of EVOO and salt.